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  <div class="section" id="s-unit-tests">
<span id="unit-tests"></span><h1>Unit tests<a class="headerlink" href="#unit-tests" title="Permalink to this headline">¶</a></h1>
<p>Django comes with a test suite of its own, in the <code class="docutils literal notranslate"><span class="pre">tests</span></code> directory of the
code base. It’s our policy to make sure all tests pass at all times.</p>
<p>We appreciate any and all contributions to the test suite!</p>
<p>The Django tests all use the testing infrastructure that ships with Django for
testing applications. See <a class="reference internal" href="../../../topics/testing/overview.html"><span class="doc">Writing and running tests</span></a> for an explanation of
how to write new tests.</p>
<div class="section" id="s-running-the-unit-tests">
<span id="s-running-unit-tests"></span><span id="running-the-unit-tests"></span><span id="running-unit-tests"></span><h2>Running the unit tests<a class="headerlink" href="#running-the-unit-tests" title="Permalink to this headline">¶</a></h2>
<div class="section" id="s-quickstart">
<span id="quickstart"></span><h3>Quickstart<a class="headerlink" href="#quickstart" title="Permalink to this headline">¶</a></h3>
<p>First, <a class="reference external" href="https://github.com/django/django/fork">fork Django on GitHub</a>.</p>
<p>Second, create and activate a virtual environment. If you’re not familiar with
how to do that, read our <a class="reference internal" href="../../../intro/contributing.html"><span class="doc">contributing tutorial</span></a>.</p>
<p>Next, clone your fork, install some requirements, and run the tests:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> git clone git@github.com:YourGitHubName/django.git django-repo
<span class="gp">$</span> <span class="nb">cd</span> django-repo/tests
<span class="gp">$</span> pip install -e ..
<span class="gp">$</span> pip install -r requirements/py3.txt  <span class="c1"># Python 2: py2.txt</span>
<span class="gp">$</span> ./runtests.py
</pre></div>
</div>
<p>Installing the requirements will likely require some operating system packages
that your computer doesn’t have installed. You can usually figure out which
package to install by doing a Web search for the last line or so of the error
message. Try adding your operating system to the search query if needed.</p>
<p>If you have trouble installing the requirements, you can skip that step, except
on Python 2, where you must <code class="docutils literal notranslate"><span class="pre">pip</span> <span class="pre">install</span> <span class="pre">mock</span></code>. See
<a class="reference internal" href="#running-unit-tests-dependencies"><span class="std std-ref">Running all the tests</span></a> for details on installing the optional
test dependencies. If you don’t have an optional dependency installed, the
tests that require it will be skipped.</p>
<p>Running the tests requires a Django settings module that defines the databases
to use. To make it easy to get started, Django provides and uses a sample
settings module that uses the SQLite database. See
<a class="reference internal" href="#running-unit-tests-settings"><span class="std std-ref">Using another settings module</span></a> to learn how to use a different settings
module to run the tests with a different database.</p>
<div class="admonition-windows-users admonition">
<p class="first admonition-title">Windows users</p>
<p class="last">We recommend something like <a class="reference external" href="https://msysgit.github.io/">Git Bash</a> to run
the tests using the above approach.</p>
</div>
<p>Having problems? See <a class="reference internal" href="#troubleshooting-unit-tests"><span class="std std-ref">Troubleshooting</span></a> for some common issues.</p>
</div>
<div class="section" id="s-running-tests-using-tox">
<span id="running-tests-using-tox"></span><h3>Running tests using <code class="docutils literal notranslate"><span class="pre">tox</span></code><a class="headerlink" href="#running-tests-using-tox" title="Permalink to this headline">¶</a></h3>
<p><a class="reference external" href="https://tox.readthedocs.io/">Tox</a> is a tool for running tests in different
virtual environments. Django includes a basic <code class="docutils literal notranslate"><span class="pre">tox.ini</span></code> that automates some
checks that our build server performs on pull requests. To run the unit tests
and other checks (such as <a class="reference internal" href="coding-style.html#coding-style-imports"><span class="std std-ref">import sorting</span></a>, the
<a class="reference internal" href="../writing-documentation.html#documentation-spelling-check"><span class="std std-ref">documentation spelling checker</span></a>, and
<a class="reference internal" href="coding-style.html#coding-style-python"><span class="std std-ref">code formatting</span></a>), install and run the <code class="docutils literal notranslate"><span class="pre">tox</span></code>
command from any place in the Django source tree:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> pip install tox
<span class="gp">$</span> tox
</pre></div>
</div>
<p>By default, <code class="docutils literal notranslate"><span class="pre">tox</span></code> runs the test suite with the bundled test settings file for
SQLite, <code class="docutils literal notranslate"><span class="pre">flake8</span></code>, <code class="docutils literal notranslate"><span class="pre">isort</span></code>, and the documentation spelling checker. In
addition to the system dependencies noted elsewhere in this documentation,
the commands <code class="docutils literal notranslate"><span class="pre">python2</span></code> and <code class="docutils literal notranslate"><span class="pre">python3</span></code> must be on your path and linked to
the appropriate versions of Python. A list of default environments can be seen
as follows:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> tox -l
<span class="go">py3</span>
<span class="go">flake8</span>
<span class="go">docs</span>
<span class="go">isort</span>
</pre></div>
</div>
<div class="section" id="s-testing-other-python-versions-and-database-backends">
<span id="testing-other-python-versions-and-database-backends"></span><h4>Testing other Python versions and database backends<a class="headerlink" href="#testing-other-python-versions-and-database-backends" title="Permalink to this headline">¶</a></h4>
<p>In addition to the default environments, <code class="docutils literal notranslate"><span class="pre">tox</span></code> supports running unit tests
for other versions of Python and other database backends. Since Django’s test
suite doesn’t bundle a settings file for database backends other than SQLite,
however, you must <a class="reference internal" href="#running-unit-tests-settings"><span class="std std-ref">create and provide your own test settings</span></a>. For example, to run the tests on Python 3.5
using PostgreSQL:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> tox -e py35-postgres -- --settings<span class="o">=</span>my_postgres_settings
</pre></div>
</div>
<p>This command sets up a Python 3.5 virtual environment, installs Django’s
test suite dependencies (including those for PostgreSQL), and calls
<code class="docutils literal notranslate"><span class="pre">runtests.py</span></code> with the supplied arguments (in this case,
<code class="docutils literal notranslate"><span class="pre">--settings=my_postgres_settings</span></code>).</p>
<p>The remainder of this documentation shows commands for running tests without
<code class="docutils literal notranslate"><span class="pre">tox</span></code>, however, any option passed to <code class="docutils literal notranslate"><span class="pre">runtests.py</span></code> can also be passed to
<code class="docutils literal notranslate"><span class="pre">tox</span></code> by prefixing the argument list with <code class="docutils literal notranslate"><span class="pre">--</span></code>, as above.</p>
<p>Tox also respects the <code class="docutils literal notranslate"><span class="pre">DJANGO_SETTINGS_MODULE</span></code> environment variable, if set.
For example, the following is equivalent to the command above:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> <span class="nv">DJANGO_SETTINGS_MODULE</span><span class="o">=</span>my_postgres_settings tox -e py35-postgres
</pre></div>
</div>
</div>
<div class="section" id="s-running-the-javascript-tests">
<span id="running-the-javascript-tests"></span><h4>Running the JavaScript tests<a class="headerlink" href="#running-the-javascript-tests" title="Permalink to this headline">¶</a></h4>
<p>Django includes a set of <a class="reference internal" href="javascript.html#javascript-tests"><span class="std std-ref">JavaScript unit tests</span></a> for
functions in certain contrib apps. The JavaScript tests aren’t run by default
using <code class="docutils literal notranslate"><span class="pre">tox</span></code> because they require <cite>Node.js</cite> to be installed and aren’t
necessary for the majority of patches. To run the JavaScript tests using
<code class="docutils literal notranslate"><span class="pre">tox</span></code>:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> tox -e javascript
</pre></div>
</div>
<p>This command runs <code class="docutils literal notranslate"><span class="pre">npm</span> <span class="pre">install</span></code> to ensure test requirements are up to
date and then runs <code class="docutils literal notranslate"><span class="pre">npm</span> <span class="pre">test</span></code>.</p>
</div>
</div>
<div class="section" id="s-using-another-settings-module">
<span id="s-running-unit-tests-settings"></span><span id="using-another-settings-module"></span><span id="running-unit-tests-settings"></span><h3>Using another <code class="docutils literal notranslate"><span class="pre">settings</span></code> module<a class="headerlink" href="#using-another-settings-module" title="Permalink to this headline">¶</a></h3>
<p>The included settings module (<code class="docutils literal notranslate"><span class="pre">tests/test_sqlite.py</span></code>) allows you to run the
test suite using SQLite. If you want to run the tests using a different
database, you’ll need to define your own settings file. Some tests, such as
those for <code class="docutils literal notranslate"><span class="pre">contrib.postgres</span></code>, are specific to a particular database backend
and will be skipped if run with a different backend.</p>
<p>To run the tests with different settings, ensure that the module is on your
<code class="docutils literal notranslate"><span class="pre">PYTHONPATH</span></code> and pass the module with <code class="docutils literal notranslate"><span class="pre">--settings</span></code>.</p>
<p>The <a class="reference internal" href="../../../ref/settings.html#std:setting-DATABASES"><code class="xref std std-setting docutils literal notranslate"><span class="pre">DATABASES</span></code></a> setting in any test settings module needs to define
two databases:</p>
<ul class="simple">
<li>A <code class="docutils literal notranslate"><span class="pre">default</span></code> database. This database should use the backend that
you want to use for primary testing.</li>
<li>A database with the alias <code class="docutils literal notranslate"><span class="pre">other</span></code>. The <code class="docutils literal notranslate"><span class="pre">other</span></code> database is used to test
that queries can be directed to different databases. This database should use
the same backend as the <code class="docutils literal notranslate"><span class="pre">default</span></code>, and it must have a different name.</li>
</ul>
<p>If you’re using a backend that isn’t SQLite, you will need to provide other
details for each database:</p>
<ul class="simple">
<li>The <a class="reference internal" href="../../../ref/settings.html#std:setting-USER"><code class="xref std std-setting docutils literal notranslate"><span class="pre">USER</span></code></a> option needs to specify an existing user account
for the database. That user needs permission to execute <code class="docutils literal notranslate"><span class="pre">CREATE</span> <span class="pre">DATABASE</span></code>
so that the test database can be created.</li>
<li>The <a class="reference internal" href="../../../ref/settings.html#std:setting-PASSWORD"><code class="xref std std-setting docutils literal notranslate"><span class="pre">PASSWORD</span></code></a> option needs to provide the password for
the <a class="reference internal" href="../../../ref/settings.html#std:setting-USER"><code class="xref std std-setting docutils literal notranslate"><span class="pre">USER</span></code></a> that has been specified.</li>
</ul>
<p>Test databases get their names by prepending <code class="docutils literal notranslate"><span class="pre">test_</span></code> to the value of the
<a class="reference internal" href="../../../ref/settings.html#std:setting-NAME"><code class="xref std std-setting docutils literal notranslate"><span class="pre">NAME</span></code></a> settings for the databases defined in <a class="reference internal" href="../../../ref/settings.html#std:setting-DATABASES"><code class="xref std std-setting docutils literal notranslate"><span class="pre">DATABASES</span></code></a>.
These test databases are deleted when the tests are finished.</p>
<p>You will also need to ensure that your database uses UTF-8 as the default
character set. If your database server doesn’t use UTF-8 as a default charset,
you will need to include a value for <a class="reference internal" href="../../../ref/settings.html#std:setting-TEST_CHARSET"><code class="xref std std-setting docutils literal notranslate"><span class="pre">CHARSET</span></code></a> in the
test settings dictionary for the applicable database.</p>
</div>
<div class="section" id="s-running-only-some-of-the-tests">
<span id="s-runtests-specifying-labels"></span><span id="running-only-some-of-the-tests"></span><span id="runtests-specifying-labels"></span><h3>Running only some of the tests<a class="headerlink" href="#running-only-some-of-the-tests" title="Permalink to this headline">¶</a></h3>
<p>Django’s entire test suite takes a while to run, and running every single test
could be redundant if, say, you just added a test to Django that you want to
run quickly without running everything else. You can run a subset of the unit
tests by appending the names of the test modules to <code class="docutils literal notranslate"><span class="pre">runtests.py</span></code> on the
command line.</p>
<p>For example, if you’d like to run tests only for generic relations and
internationalization, type:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> ./runtests.py --settings<span class="o">=</span>path.to.settings generic_relations i18n
</pre></div>
</div>
<p>How do you find out the names of individual tests? Look in <code class="docutils literal notranslate"><span class="pre">tests/</span></code> — each
directory name there is the name of a test.</p>
<p>If you just want to run a particular class of tests, you can specify a list of
paths to individual test classes. For example, to run the <code class="docutils literal notranslate"><span class="pre">TranslationTests</span></code>
of the <code class="docutils literal notranslate"><span class="pre">i18n</span></code> module, type:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> ./runtests.py --settings<span class="o">=</span>path.to.settings i18n.tests.TranslationTests
</pre></div>
</div>
<p>Going beyond that, you can specify an individual test method like this:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> ./runtests.py --settings<span class="o">=</span>path.to.settings i18n.tests.TranslationTests.test_lazy_objects
</pre></div>
</div>
</div>
<div class="section" id="s-running-the-selenium-tests">
<span id="running-the-selenium-tests"></span><h3>Running the Selenium tests<a class="headerlink" href="#running-the-selenium-tests" title="Permalink to this headline">¶</a></h3>
<p>Some tests require Selenium and a Web browser. To run these tests, you must
install the <a class="reference external" href="https://pypi.python.org/pypi/selenium">selenium</a> package and run the tests with the
<code class="docutils literal notranslate"><span class="pre">--selenium=&lt;BROWSERS&gt;</span></code> option. For example, if you have Firefox and Google
Chrome installed:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> ./runtests.py --selenium<span class="o">=</span>firefox,chrome
</pre></div>
</div>
<p>See the <a class="reference external" href="https://github.com/SeleniumHQ/selenium/tree/master/py/selenium/webdriver">selenium.webdriver</a> package for the list of available browsers.</p>
<p>Specifying <code class="docutils literal notranslate"><span class="pre">--selenium</span></code> automatically sets <code class="docutils literal notranslate"><span class="pre">--tags=selenium</span></code> to run only
the tests that require selenium.</p>
</div>
<div class="section" id="s-running-all-the-tests">
<span id="s-running-unit-tests-dependencies"></span><span id="running-all-the-tests"></span><span id="running-unit-tests-dependencies"></span><h3>Running all the tests<a class="headerlink" href="#running-all-the-tests" title="Permalink to this headline">¶</a></h3>
<p>If you want to run the full suite of tests, you’ll need to install a number of
dependencies:</p>
<ul class="simple">
<li><a class="reference external" href="https://pypi.python.org/pypi/argon2_cffi">argon2-cffi</a> 16.1.0+</li>
<li><a class="reference external" href="https://pypi.python.org/pypi/bcrypt">bcrypt</a></li>
<li><a class="reference external" href="https://pypi.python.org/pypi/docutils">docutils</a></li>
<li><a class="reference external" href="https://pypi.python.org/pypi/enum34">enum34</a> (Python 2 only)</li>
<li><a class="reference external" href="https://pypi.python.org/pypi/geoip2">geoip2</a></li>
<li><a class="reference external" href="https://pypi.python.org/pypi/jinja2">jinja2</a> 2.7+</li>
<li><a class="reference external" href="https://pypi.python.org/pypi/numpy">numpy</a></li>
<li><a class="reference external" href="https://pypi.python.org/pypi/Pillow/">Pillow</a></li>
<li><a class="reference external" href="http://pyyaml.org/wiki/PyYAML">PyYAML</a></li>
<li><a class="reference external" href="https://pypi.python.org/pypi/pytz/">pytz</a> (required)</li>
<li><a class="reference external" href="https://pypi.python.org/pypi/setuptools/">setuptools</a></li>
<li><a class="reference external" href="http://memcached.org/">memcached</a>, plus a <a class="reference internal" href="../../../topics/cache.html#memcached"><span class="std std-ref">supported Python binding</span></a></li>
<li><a class="reference external" href="https://pypi.python.org/pypi/mock">mock</a> (for Python 2)</li>
<li><a class="reference external" href="https://www.gnu.org/software/gettext/manual/gettext.html">gettext</a> (<a class="reference internal" href="../../../topics/i18n/translation.html#gettext-on-windows"><span class="std std-ref">gettext on Windows</span></a>)</li>
<li><a class="reference external" href="https://pypi.python.org/pypi/selenium">selenium</a></li>
<li><a class="reference external" href="https://pypi.python.org/pypi/sqlparse">sqlparse</a></li>
</ul>
<p>You can find these dependencies in <a class="reference external" href="https://pip.pypa.io/en/latest/user_guide/#requirements-files">pip requirements files</a> inside the
<code class="docutils literal notranslate"><span class="pre">tests/requirements</span></code> directory of the Django source tree and install them
like so:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> pip install -r tests/requirements/py3.txt  <span class="c1"># Python 2: py2.txt</span>
</pre></div>
</div>
<p>If you encounter an error during the installation, your system might be missing
a dependency for one or more of the Python packages. Consult the failing
package’s documentation or search the Web with the error message that you
encounter.</p>
<p>You can also install the database adapter(s) of your choice using
<code class="docutils literal notranslate"><span class="pre">oracle.txt</span></code>, <code class="docutils literal notranslate"><span class="pre">mysql.txt</span></code>, or <code class="docutils literal notranslate"><span class="pre">postgres.txt</span></code>.</p>
<p>If you want to test the memcached cache backend, you’ll also need to define
a <a class="reference internal" href="../../../ref/settings.html#std:setting-CACHES"><code class="xref std std-setting docutils literal notranslate"><span class="pre">CACHES</span></code></a> setting that points at your memcached instance.</p>
<p>To run the GeoDjango tests, you will need to <a class="reference internal" href="../../../ref/contrib/gis/install/index.html"><span class="doc">setup a spatial database
and install the Geospatial libraries</span></a>.</p>
<p>Each of these dependencies is optional. If you’re missing any of them, the
associated tests will be skipped.</p>
</div>
<div class="section" id="s-code-coverage">
<span id="code-coverage"></span><h3>Code coverage<a class="headerlink" href="#code-coverage" title="Permalink to this headline">¶</a></h3>
<p>Contributors are encouraged to run coverage on the test suite to identify areas
that need additional tests. The coverage tool installation and use is described
in <a class="reference internal" href="../../../topics/testing/advanced.html#topics-testing-code-coverage"><span class="std std-ref">testing code coverage</span></a>.</p>
<p>Coverage should be run in a single process to obtain accurate statistics. To
run coverage on the Django test suite using the standard test settings:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> coverage run ./runtests.py --settings<span class="o">=</span>test_sqlite --parallel<span class="o">=</span><span class="m">1</span>
</pre></div>
</div>
<p>After running coverage, generate the html report by running:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> coverage html
</pre></div>
</div>
<p>When running coverage for the Django tests, the included <code class="docutils literal notranslate"><span class="pre">.coveragerc</span></code>
settings file  defines <code class="docutils literal notranslate"><span class="pre">coverage_html</span></code> as the output directory for the report
and also excludes several directories not relevant to the results
(test code or external code included in Django).</p>
</div>
</div>
<div class="section" id="s-contrib-apps">
<span id="s-id1"></span><span id="contrib-apps"></span><span id="id1"></span><h2>Contrib apps<a class="headerlink" href="#contrib-apps" title="Permalink to this headline">¶</a></h2>
<p>Tests for contrib apps can be found in the <code class="docutils literal notranslate"><span class="pre">tests/</span></code> directory, typically
under <code class="docutils literal notranslate"><span class="pre">&lt;app_name&gt;_tests</span></code>. For example, tests for <code class="docutils literal notranslate"><span class="pre">contrib.auth</span></code> are located
in <code class="docutils literal notranslate"><span class="pre">tests/auth_tests</span></code>.</p>
</div>
<div class="section" id="s-troubleshooting">
<span id="s-troubleshooting-unit-tests"></span><span id="troubleshooting"></span><span id="troubleshooting-unit-tests"></span><h2>Troubleshooting<a class="headerlink" href="#troubleshooting" title="Permalink to this headline">¶</a></h2>
<div class="section" id="s-many-test-failures-with-unicodeencodeerror">
<span id="many-test-failures-with-unicodeencodeerror"></span><h3>Many test failures with <code class="docutils literal notranslate"><span class="pre">UnicodeEncodeError</span></code><a class="headerlink" href="#many-test-failures-with-unicodeencodeerror" title="Permalink to this headline">¶</a></h3>
<p>If the <code class="docutils literal notranslate"><span class="pre">locales</span></code> package is not installed, some tests will fail with a
<code class="docutils literal notranslate"><span class="pre">UnicodeEncodeError</span></code>.</p>
<p>You can resolve this on Debian-based systems, for example, by running:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> apt-get install locales
<span class="gp">$</span> dpkg-reconfigure locales
</pre></div>
</div>
<p>You can resolve this for macOS systems by configuring your shell’s locale:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> <span class="nb">export</span> <span class="nv">LANG</span><span class="o">=</span><span class="s2">&quot;en_US.UTF-8&quot;</span>
<span class="gp">$</span> <span class="nb">export</span> <span class="nv">LC_ALL</span><span class="o">=</span><span class="s2">&quot;en_US.UTF-8&quot;</span>
</pre></div>
</div>
<p>Run the <code class="docutils literal notranslate"><span class="pre">locale</span></code> command to confirm the change. Optionally, add those export
commands to your shell’s startup file (e.g. <code class="docutils literal notranslate"><span class="pre">~/.bashrc</span></code> for Bash) to avoid
having to retype them.</p>
</div>
<div class="section" id="s-tests-that-only-fail-in-combination">
<span id="tests-that-only-fail-in-combination"></span><h3>Tests that only fail in combination<a class="headerlink" href="#tests-that-only-fail-in-combination" title="Permalink to this headline">¶</a></h3>
<p>In case a test passes when run in isolation but fails within the whole suite,
we have some tools to help analyze the problem.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">--bisect</span></code> option of <code class="docutils literal notranslate"><span class="pre">runtests.py</span></code> will run the failing test while
halving the test set it is run together with on each iteration, often making
it possible to identify a small number of tests that may be related to the
failure.</p>
<p>For example, suppose that the failing test that works on its own is
<code class="docutils literal notranslate"><span class="pre">ModelTest.test_eq</span></code>, then using:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> ./runtests.py --bisect basic.tests.ModelTest.test_eq
</pre></div>
</div>
<p>will try to determine a test that interferes with the given one. First, the
test is run with the first half of the test suite. If a failure occurs, the
first half of the test suite is split in two groups and each group is then run
with the specified test. If there is no failure with the first half of the test
suite, the second half of the test suite is run with the specified test and
split appropriately as described earlier. The process repeats until the set of
failing tests is minimized.</p>
<p>The <code class="docutils literal notranslate"><span class="pre">--pair</span></code> option runs the given test alongside every other test from the
suite, letting you check if another test has side-effects that cause the
failure. So:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> ./runtests.py --pair basic.tests.ModelTest.test_eq
</pre></div>
</div>
<p>will pair <code class="docutils literal notranslate"><span class="pre">test_eq</span></code> with every test label.</p>
<p>With both <code class="docutils literal notranslate"><span class="pre">--bisect</span></code> and <code class="docutils literal notranslate"><span class="pre">--pair</span></code>, if you already suspect which cases
might be responsible for the failure, you may limit tests to be cross-analyzed
by <a class="reference internal" href="#runtests-specifying-labels"><span class="std std-ref">specifying further test labels</span></a> after
the first one:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> ./runtests.py --pair basic.tests.ModelTest.test_eq queries transactions
</pre></div>
</div>
<p>You can also try running any set of tests in reverse using the <code class="docutils literal notranslate"><span class="pre">--reverse</span></code>
option in order to verify that executing tests in a different order does not
cause any trouble:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> ./runtests.py basic --reverse
</pre></div>
</div>
</div>
<div class="section" id="s-seeing-the-sql-queries-run-during-a-test">
<span id="seeing-the-sql-queries-run-during-a-test"></span><h3>Seeing the SQL queries run during a test<a class="headerlink" href="#seeing-the-sql-queries-run-during-a-test" title="Permalink to this headline">¶</a></h3>
<p>If you wish to examine the SQL being run in failing tests, you can turn on
<a class="reference internal" href="../../../topics/logging.html#django-db-logger"><span class="std std-ref">SQL logging</span></a> using the <code class="docutils literal notranslate"><span class="pre">--debug-sql</span></code> option. If you
combine this with <code class="docutils literal notranslate"><span class="pre">--verbosity=2</span></code>, all SQL queries will be output:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> ./runtests.py basic --debug-sql
</pre></div>
</div>
</div>
<div class="section" id="s-seeing-the-full-traceback-of-a-test-failure">
<span id="seeing-the-full-traceback-of-a-test-failure"></span><h3>Seeing the full traceback of a test failure<a class="headerlink" href="#seeing-the-full-traceback-of-a-test-failure" title="Permalink to this headline">¶</a></h3>
<p>By default tests are run in parallel with one process per core. When the tests
are run in parallel, however, you’ll only see a truncated traceback for any
test failures. You can adjust this behavior with the <code class="docutils literal notranslate"><span class="pre">--parallel</span></code> option:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="gp">$</span> ./runtests.py basic --parallel<span class="o">=</span><span class="m">1</span>
</pre></div>
</div>
<p>You can also use the <code class="docutils literal notranslate"><span class="pre">DJANGO_TEST_PROCESSES</span></code> environment variable for this
purpose.</p>
</div>
<div class="section" id="s-tips-for-writing-tests">
<span id="tips-for-writing-tests"></span><h3>Tips for writing tests<a class="headerlink" href="#tips-for-writing-tests" title="Permalink to this headline">¶</a></h3>
<div class="section" id="s-isolating-model-registration">
<span id="isolating-model-registration"></span><h4>Isolating model registration<a class="headerlink" href="#isolating-model-registration" title="Permalink to this headline">¶</a></h4>
<p>To avoid polluting the global <a class="reference internal" href="../../../ref/applications.html#django.apps.apps" title="django.apps.apps"><code class="xref py py-attr docutils literal notranslate"><span class="pre">apps</span></code></a> registry and prevent
unnecessary table creation, models defined in a test method should be bound to
a temporary <code class="docutils literal notranslate"><span class="pre">Apps</span></code> instance:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">django.apps.registry</span> <span class="kn">import</span> <span class="n">Apps</span>
<span class="kn">from</span> <span class="nn">django.db</span> <span class="kn">import</span> <span class="n">models</span>
<span class="kn">from</span> <span class="nn">django.test</span> <span class="kn">import</span> <span class="n">SimpleTestCase</span>

<span class="k">class</span> <span class="nc">TestModelDefinition</span><span class="p">(</span><span class="n">SimpleTestCase</span><span class="p">):</span>
    <span class="k">def</span> <span class="nf">test_model_definition</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="n">test_apps</span> <span class="o">=</span> <span class="n">Apps</span><span class="p">([</span><span class="s1">&#39;app_label&#39;</span><span class="p">])</span>

        <span class="k">class</span> <span class="nc">TestModel</span><span class="p">(</span><span class="n">models</span><span class="o">.</span><span class="n">Model</span><span class="p">):</span>
            <span class="k">class</span> <span class="nc">Meta</span><span class="p">:</span>
                <span class="n">apps</span> <span class="o">=</span> <span class="n">test_apps</span>
        <span class="o">...</span>
</pre></div>
</div>
<dl class="function">
<dt id="django.test.utils.isolate_apps">
<code class="descclassname">django.test.utils.</code><code class="descname">isolate_apps</code>(<em>*app_labels</em>, <em>attr_name=None</em>, <em>kwarg_name=None</em>)<a class="headerlink" href="#django.test.utils.isolate_apps" title="Permalink to this definition">¶</a></dt>
<dd></dd></dl>

<div class="versionadded">
<span class="title">New in Django 1.10.</span> </div>
<p>Since this pattern involves a lot of boilerplate, Django provides the
<a class="reference internal" href="#django.test.utils.isolate_apps" title="django.test.utils.isolate_apps"><code class="xref py py-func docutils literal notranslate"><span class="pre">isolate_apps()</span></code></a> decorator. It’s used like this:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">django.db</span> <span class="kn">import</span> <span class="n">models</span>
<span class="kn">from</span> <span class="nn">django.test</span> <span class="kn">import</span> <span class="n">SimpleTestCase</span>
<span class="kn">from</span> <span class="nn">django.test.utils</span> <span class="kn">import</span> <span class="n">isolate_apps</span>

<span class="k">class</span> <span class="nc">TestModelDefinition</span><span class="p">(</span><span class="n">SimpleTestCase</span><span class="p">):</span>
    <span class="nd">@isolate_apps</span><span class="p">(</span><span class="s1">&#39;app_label&#39;</span><span class="p">)</span>
    <span class="k">def</span> <span class="nf">test_model_definition</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="k">class</span> <span class="nc">TestModel</span><span class="p">(</span><span class="n">models</span><span class="o">.</span><span class="n">Model</span><span class="p">):</span>
            <span class="k">pass</span>
        <span class="o">...</span>
</pre></div>
</div>
<div class="admonition-setting-app-label admonition">
<p class="first admonition-title">Setting <code class="docutils literal notranslate"><span class="pre">app_label</span></code></p>
<p>Models defined in a test method with no explicit
<a class="reference internal" href="../../../ref/models/options.html#django.db.models.Options.app_label" title="django.db.models.Options.app_label"><code class="xref py py-attr docutils literal notranslate"><span class="pre">app_label</span></code></a> are automatically assigned the
label of the app in which their test class is located.</p>
<p>In order to make sure the models defined within the context of
<a class="reference internal" href="#django.test.utils.isolate_apps" title="django.test.utils.isolate_apps"><code class="xref py py-func docutils literal notranslate"><span class="pre">isolate_apps()</span></code></a> instances are correctly
installed, you should pass the set of targeted <code class="docutils literal notranslate"><span class="pre">app_label</span></code> as arguments:</p>
<div class="last highlight-default snippet"><div class="snippet-filename">tests/app_label/tests.py</div>
<div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">django.db</span> <span class="k">import</span> <span class="n">models</span>
<span class="kn">from</span> <span class="nn">django.test</span> <span class="k">import</span> <span class="n">SimpleTestCase</span>
<span class="kn">from</span> <span class="nn">django.test.utils</span> <span class="k">import</span> <span class="n">isolate_apps</span>

<span class="k">class</span> <span class="nc">TestModelDefinition</span><span class="p">(</span><span class="n">SimpleTestCase</span><span class="p">):</span>
    <span class="nd">@isolate_apps</span><span class="p">(</span><span class="s1">&#39;app_label&#39;</span><span class="p">,</span> <span class="s1">&#39;other_app_label&#39;</span><span class="p">)</span>
    <span class="k">def</span> <span class="nf">test_model_definition</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="c1"># This model automatically receives app_label=&#39;app_label&#39;</span>
        <span class="k">class</span> <span class="nc">TestModel</span><span class="p">(</span><span class="n">models</span><span class="o">.</span><span class="n">Model</span><span class="p">):</span>
            <span class="k">pass</span>

        <span class="k">class</span> <span class="nc">OtherAppModel</span><span class="p">(</span><span class="n">models</span><span class="o">.</span><span class="n">Model</span><span class="p">):</span>
            <span class="k">class</span> <span class="nc">Meta</span><span class="p">:</span>
                <span class="n">app_label</span> <span class="o">=</span> <span class="s1">&#39;other_app_label&#39;</span>
        <span class="o">...</span>
</pre></div>
</div>
</div>
<p>The decorator can also be applied to classes:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">django.db</span> <span class="kn">import</span> <span class="n">models</span>
<span class="kn">from</span> <span class="nn">django.test</span> <span class="kn">import</span> <span class="n">SimpleTestCase</span>
<span class="kn">from</span> <span class="nn">django.test.utils</span> <span class="kn">import</span> <span class="n">isolate_apps</span>

<span class="nd">@isolate_apps</span><span class="p">(</span><span class="s1">&#39;app_label&#39;</span><span class="p">)</span>
<span class="k">class</span> <span class="nc">TestModelDefinition</span><span class="p">(</span><span class="n">SimpleTestCase</span><span class="p">):</span>
    <span class="k">def</span> <span class="nf">test_model_definition</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="k">class</span> <span class="nc">TestModel</span><span class="p">(</span><span class="n">models</span><span class="o">.</span><span class="n">Model</span><span class="p">):</span>
            <span class="k">pass</span>
        <span class="o">...</span>
</pre></div>
</div>
<p>The temporary <code class="docutils literal notranslate"><span class="pre">Apps</span></code> instance used to isolate model registration can be
retrieved as an attribute when used as a class decorator by using the
<code class="docutils literal notranslate"><span class="pre">attr_name</span></code> parameter:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">django.db</span> <span class="kn">import</span> <span class="n">models</span>
<span class="kn">from</span> <span class="nn">django.test</span> <span class="kn">import</span> <span class="n">SimpleTestCase</span>
<span class="kn">from</span> <span class="nn">django.test.utils</span> <span class="kn">import</span> <span class="n">isolate_apps</span>

<span class="nd">@isolate_apps</span><span class="p">(</span><span class="s1">&#39;app_label&#39;</span><span class="p">,</span> <span class="n">attr_name</span><span class="o">=</span><span class="s1">&#39;apps&#39;</span><span class="p">)</span>
<span class="k">class</span> <span class="nc">TestModelDefinition</span><span class="p">(</span><span class="n">SimpleTestCase</span><span class="p">):</span>
    <span class="k">def</span> <span class="nf">test_model_definition</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
        <span class="k">class</span> <span class="nc">TestModel</span><span class="p">(</span><span class="n">models</span><span class="o">.</span><span class="n">Model</span><span class="p">):</span>
            <span class="k">pass</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">assertIs</span><span class="p">(</span><span class="bp">self</span><span class="o">.</span><span class="n">apps</span><span class="o">.</span><span class="n">get_model</span><span class="p">(</span><span class="s1">&#39;app_label&#39;</span><span class="p">,</span> <span class="s1">&#39;TestModel&#39;</span><span class="p">),</span> <span class="n">TestModel</span><span class="p">)</span>
</pre></div>
</div>
<p>Or as an argument on the test method when used as a method decorator by using
the <code class="docutils literal notranslate"><span class="pre">kwarg_name</span></code> parameter:</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <span class="nn">django.db</span> <span class="kn">import</span> <span class="n">models</span>
<span class="kn">from</span> <span class="nn">django.test</span> <span class="kn">import</span> <span class="n">SimpleTestCase</span>
<span class="kn">from</span> <span class="nn">django.test.utils</span> <span class="kn">import</span> <span class="n">isolate_apps</span>

<span class="k">class</span> <span class="nc">TestModelDefinition</span><span class="p">(</span><span class="n">SimpleTestCase</span><span class="p">):</span>
    <span class="nd">@isolate_apps</span><span class="p">(</span><span class="s1">&#39;app_label&#39;</span><span class="p">,</span> <span class="n">kwarg_name</span><span class="o">=</span><span class="s1">&#39;apps&#39;</span><span class="p">)</span>
    <span class="k">def</span> <span class="nf">test_model_definition</span><span class="p">(</span><span class="bp">self</span><span class="p">,</span> <span class="n">apps</span><span class="p">):</span>
        <span class="k">class</span> <span class="nc">TestModel</span><span class="p">(</span><span class="n">models</span><span class="o">.</span><span class="n">Model</span><span class="p">):</span>
            <span class="k">pass</span>
        <span class="bp">self</span><span class="o">.</span><span class="n">assertIs</span><span class="p">(</span><span class="n">apps</span><span class="o">.</span><span class="n">get_model</span><span class="p">(</span><span class="s1">&#39;app_label&#39;</span><span class="p">,</span> <span class="s1">&#39;TestModel&#39;</span><span class="p">),</span> <span class="n">TestModel</span><span class="p">)</span>
</pre></div>
</div>
</div>
</div>
</div>
</div>


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  <h3><a href="../../../contents.html">Table of Contents</a></h3>
  <ul>
<li><a class="reference internal" href="#">Unit tests</a><ul>
<li><a class="reference internal" href="#running-the-unit-tests">Running the unit tests</a><ul>
<li><a class="reference internal" href="#quickstart">Quickstart</a></li>
<li><a class="reference internal" href="#running-tests-using-tox">Running tests using <code class="docutils literal notranslate"><span class="pre">tox</span></code></a><ul>
<li><a class="reference internal" href="#testing-other-python-versions-and-database-backends">Testing other Python versions and database backends</a></li>
<li><a class="reference internal" href="#running-the-javascript-tests">Running the JavaScript tests</a></li>
</ul>
</li>
<li><a class="reference internal" href="#using-another-settings-module">Using another <code class="docutils literal notranslate"><span class="pre">settings</span></code> module</a></li>
<li><a class="reference internal" href="#running-only-some-of-the-tests">Running only some of the tests</a></li>
<li><a class="reference internal" href="#running-the-selenium-tests">Running the Selenium tests</a></li>
<li><a class="reference internal" href="#running-all-the-tests">Running all the tests</a></li>
<li><a class="reference internal" href="#code-coverage">Code coverage</a></li>
</ul>
</li>
<li><a class="reference internal" href="#contrib-apps">Contrib apps</a></li>
<li><a class="reference internal" href="#troubleshooting">Troubleshooting</a><ul>
<li><a class="reference internal" href="#many-test-failures-with-unicodeencodeerror">Many test failures with <code class="docutils literal notranslate"><span class="pre">UnicodeEncodeError</span></code></a></li>
<li><a class="reference internal" href="#tests-that-only-fail-in-combination">Tests that only fail in combination</a></li>
<li><a class="reference internal" href="#seeing-the-sql-queries-run-during-a-test">Seeing the SQL queries run during a test</a></li>
<li><a class="reference internal" href="#seeing-the-full-traceback-of-a-test-failure">Seeing the full traceback of a test failure</a></li>
<li><a class="reference internal" href="#tips-for-writing-tests">Tips for writing tests</a><ul>
<li><a class="reference internal" href="#isolating-model-registration">Isolating model registration</a></li>
</ul>
</li>
</ul>
</li>
</ul>
</li>
</ul>

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